4,513 research outputs found
Place Accumulation: Kingston/Ulster
Since February 2018, I’ve been listening and recording around Kingston and the town of Ulster; synthesizing interviews, bird song, passing cars, protests, conflict, unique perspectives and oral histories, meetings, optimisms, water, as part of a project called, Place Accumulation: Kingston/Ulster. Using the Dynamic Listening Instrument, an interactive sound sculpture which uses a venn-diagram of electromagnetic fields to allow sounds to be handled as a tactile entity and bended dynamically, sounds are arranged and dispersed back into different locations and events in Kingston. Using a sounding bucket, people in Kingston can listen in, re-arrange, explore, and play with sounds from their overlapping and opposed publics and environments.
My trajectories of enquiry started with a public scoping meeting about the company GlidePath’s proposed fossil fuel plant to be built behind the Hudson Valley Mall, a “We Want a Dream Act Now!” demonstration on Broadway, and a Police Community relations forum at City Hall. These trajectories were followed and have led to intimate collaboration, opportunities for unique sonic exchange, and expanded enquiry and listening.
This project started as a way to use the Dynamic Listening Instrument for and with a place and community, to amplify, map, and transduce relationships between public space, ecology, and empathy. With collaborations, friendships, occupation of public space, attentive listening and open hanging out and deep listening, the Dynamic Listening Instrument introduces a new type of social feedback to a place and community
EVLA Observations of OH Masers in ON 1
This Letter reports on initial Expanded Very Large Array (EVLA) observations
of the 6035 MHz masers in ON 1. The EVLA data are of good quality, lending
confidence in the new receiver system. Nineteen maser features, including six
Zeeman pairs, are detected. The overall distribution of 6035 MHz OH masers is
similar to that of the 1665 MHz OH masers. The spatial resolution is sufficient
to unambiguously determine that the magnetic field is strong (~ -10 mG) at the
location of the blueshifted masers in the north, consistent with Zeeman
splitting detected in 13441 MHz OH masers in the same velocity range. Left and
right circularly polarized ground-state features dominate in different regions
in the north of the source, which may be due to a combination of magnetic field
and velocity gradients. The combined distribution of all OH masers toward the
south is suggestive of a shock structure of the sort previously seen in W3(OH).Comment: 4 pages using emulateapj.cls including 2 tables and 2 color figure
Energetics of locomotion by the Australian Water Rat (Hydromys Chrysogaster): A comparison of swimming and running in a semi-aquatic mammal
© The Company of BiologistsSemi-aquatic mammals occupy a precarious evolutionary position, having to function in both aquatic and terrestrial environments without specializing in locomotor performance in either environment. To examine possible energetic constraints on semi-aquatic mammals, we compared rates of oxygen consumption for the Australian water rat (Hydromys chrysogaster) using different locomotor behaviors: swimming and running. Aquatic locomotion was investigated as animals swam in a water flume at several speeds, whereas water rats were run on a treadmill to measure metabolic effort during terrestrial locomotion. Water rats swam at the surface using alternate pelvic paddling and locomoted on the treadmill using gaits that included walk, trot and half-bound. Water rats were able to run at twice their maximum swimming velocity. Swimming metabolic rate increased with velocity in a pattern similar to the 'humps' and 'hollows' for wave drag experienced by bodies moving at the water surface. Metabolic rate increased linearly during running. Over equivalent velocities, the metabolic rate for running was 13-40 % greater than for swimming. The minimum cost of transport for swimming (2.61 J N-1 m-1) was equivalent to values for other semi-aquatic mammals. The lowest cost for running (2.08 J N-1 m-1) was 20 % lower than for swimming. When compared with specialists at the extremes of the terrestrial-aquatic continuum, the energetic costs of locomoting either in water or on land were high for the semi-aquatic Hydromys chrysogaster. However, the relative costs for H. chrysogaster were lower than when an aquatic specialist attempts to move on land or a terrestrial specialist attempts to swim.F.E. Fish and R.V. Baudinett
Mesospheric Motions Over Bear Lake
Since February 1999, the Utah State University Bear Lake Observatory (41.9oN, 111.4oW) dynasonde has been configured to operate as an Imaging Doppler Interferometer (IDI). Imaging Doppler interferometry is one of a number of MF/HF radar techniques used to estimate mesospheric winds and dynamics. This paper presents results of the mesospheric (50 – 115 km) background wind, tides, and planetary waves as derived from analysis of IDI observations recorded between February 03, 1999 and February 21, 2000 at Bear Lake
Relative Astrometry of Compact Flaring Structures in Sgr A* with Polarimetric VLBI
We demonstrate that polarimetric interferometry can be used to extract
precise spatial information about compact polarized flares of Sgr A*. We show
that, for a faint dynamical component, a single interferometric baseline
suffices to determine both its polarization and projected displacement from the
quiescent intensity centroid. A second baseline enables two-dimensional
reconstruction of the displacement, and additional baselines can self-calibrate
using the flare, enhancing synthesis imaging of the quiescent emission. We
apply this technique to simulated 1.3-mm wavelength observations of a "hot
spot" embedded in a radiatively inefficient accretion disk around Sgr A*. Our
results indicate that, even with current sensitivities, polarimetric
interferometry with the Event Horizon Telescope can achieve ~5 microarcsecond
relative astrometry of compact flaring structures near Sgr A* on timescales of
minutes.Comment: 9 Pages, 4 Figures, accepted for publication in Ap
Homogenization of the one-dimensional wave equation
We present a method for two-scale model derivation of the periodic
homogenization of the one-dimensional wave equation in a bounded domain. It
allows for analyzing the oscillations occurring on both microscopic and
macroscopic scales. The novelty reported here is on the asymptotic behavior of
high frequency waves and especially on the boundary conditions of the
homogenized equation. Numerical simulations are reported
Disparity in the natural cycles of Borrelia burgdorferi and the agent of human granulocytic ehrlichiosis.
We studied the prevalence of Borrelia burgdorferi and the agent of human granulocytic ehrlichiosis (HGE) among questing nymphal and adult Ixodes scapularis ticks of the same generation and the infectivity of wild white-footed mice for ticks feeding on them. The prevalence of B. burgdorferi infection in host-seeking ticks increased less than twofold from nymphal (31% to 33%) to adult (52% to 56%) stage, and 52% of white-footed mice were infected. Prevalence of the agent of HGE increased 4.5- to 10.6-fold from nymphal (1.5% to 1.8%) to adult stage (7.6% to 19.0%), while only 18% of mice were infectious to ticks. B. burgdorferi infection was more common in mouse-fed ticks than in ticks collected from vegetation, whereas the agent of HGE was half as common in mouse-fed ticks as in ticks collected from vegetation. The different prevalence in nature of these pathogens in ticks suggests that their maintenance cycles are also different
Imaging an Event Horizon: Mitigation of Source Variability of Sagittarius A*
The black hole in the center of the Galaxy, associated with the compact
source Sagittarius A* (Sgr A*), is predicted to cast a shadow upon the emission
of the surrounding plasma flow, which encodes the influence of general
relativity in the strong-field regime. The Event Horizon Telescope (EHT) is a
Very Long Baseline Interferometry (VLBI) network with a goal of imaging nearby
supermassive black holes (in particular Sgr A* and M87) with angular resolution
sufficient to observe strong gravity effects near the event horizon. General
relativistic magnetohydrodynamic (GRMHD) simulations show that radio emission
from Sgr A* exhibits vari- ability on timescales of minutes, much shorter than
the duration of a typical VLBI imaging experiment, which usually takes several
hours. A changing source structure during the observations, however, violates
one of the basic assumptions needed for aperture synthesis in radio
interferometry imaging to work. By simulating realistic EHT observations of a
model movie of Sgr A*, we demonstrate that an image of the average quiescent
emission, featuring the characteristic black hole shadow and photon ring
predicted by general relativity, can nonetheless be obtained by observing over
multiple days and subsequent processing of the visibilities (scaling,
averaging, and smoothing) before imaging. Moreover, it is shown that this
procedure can be combined with an existing method to mitigate the effects of
interstellar scattering. Taken together, these techniques allow the black hole
shadow in the Galactic center to be recovered on the reconstructed image.Comment: 10 pages, 12figures, accepted for publication in Ap
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